Pharmaceutically active agents are generally formulated as solid or liquid dosage forms for administration. Such dosage forms generally comprise the active agent combined with excipients to form materials that may be conveniently and reliably administered to a patient in need of such therapy, and following administration, the active agent is absorbed and distributed in the patient in a way that leads to good efficacy and safety.
Cationic polymers have previously been used for extended or controlled release of active agents near the site of delivery. Some cationic polymers have been evaluated for this purpose and in some cases have been referred to as “mucoadhesive.” Examples of cationic mucoadhesive excipients include chitin, chitosan, and amino-substituted polyacrylates and polymethacrylates.